Events of 1343

• January 27 - Pope Clement VI issues his Bull Unigenitus, defining the doctrine of "The Treasury of Merits" or "The Treasury of the Church" as the basis for the issuance of indulgences by the Catholic Church.
• April 23 - The St. George's Night Uprising occurs in Estonia (-1345).

• August 15 - Magnus II of Sweden abdicates from the throne of Norway in favor of his son Haakon VI of Norway. However Haakon is still a minor, allowing Magnus to remain de facto ruler.

Births

• July 23 - Thomas Percy, 1st Earl of Worcester, English rebel (d. 1403)
• date unknown
• Emperor Chokei of Japan (d. 1394)
• Constança of Aragon, queen consort of Sicily (d. 1363)
• Tommaso Mocenigo, doge of Venice (d. 1423)
• Paolo Alboino della Scala, lord of Verona (d. 1375)
• Alexander Stewart, 1st Earl of Buchan (d. 1394)
• probable - Geoffrey Chaucer, English poet (approximate date) (d. 1400)

Deaths

• January 20 - Robert of Naples (b. 1277)
• May 29 - Francesco I Manfredi, lord of Faenza
• June 23 - Giacomo Gaetani Stefaneschi, Italian cardinal (b. c. 1270)
• September 16 - Philip III of Navarre (b. 1306)
• December 15 - Hasan Kucek, Chobanid prince (b. c. 1319)
• date unknown
• Sir Ulick Burke, Irish nobleman
• Aimone, Count of Savoy (b. 1291)
• Veera Ballala III, ruler of the Hoysala Empire (b. 1291)